ARTICLE | doi:10.20944/preprints202305.1361.v1
Subject: Biology And Life Sciences, Virology Keywords: COVID-19; SARS-CoV-2; Omicron Variant of Concern; Mutations; Lineages
Online: 19 May 2023 (03:00:56 CEST)
The emergence of the SARS-CoV-2 Variant of Concern (VOC) Omicron has been characterized by an explosive number of cases in almost every part of the world. The dissemination of different sub-lineages and recombinant genomes also led to several posterior waves in many countries. The circulation of this VOC and its major sub-lineages (BA.1 to BA.5) was monitored in community cases and in international travelers returning to Venezuela, by a rapid partial sequencing method. The specific sub-lineage assignment was performed by complete genome sequencing. Epidemic waves of SARS-CoV-2 cases were observed among international travelers during 2022, a situation not seen before December 2021. The succession of the Omicron VOC sub-lineages BA.1 to BA.5 occurred sequentially, except for BA.3, which was almost not detected. However, the sub-lineages generally circulated two months earlier in international travelers than in community cases. The diversity of Omicron sub-lineages found in international travelers was related to the one found in the USA, consistent with the most frequent destination of international travel from Venezuela this year. These differences are compatible with the delay observed in Latin American countries in the circulation of the different lineages of the Omicron VOC.
ARTICLE | doi:10.20944/preprints202205.0247.v1
Subject: Biology And Life Sciences, Virology Keywords: COVID-19; SARS-CoV-2; Variants of Concern; Rapid screening; Mutations
Online: 19 May 2022 (03:31:36 CEST)
Some of the lineages of SARS-CoV-2, the new coronavirus responsible for COVID-19, exhibit higher transmissibility or partial resistance to antibody mediated neutralization and were des-ignated by WHO as Variants of Interests (VOIs) or Concern (VOCs). The aim of this study was to monitor the dissemination of VOIs and VOCs in Venezuela during a year. A 614 nt genomic fragment was sequenced for the detection of some relevant mutations of these variants. Their presence was confirmed by complete genome sequencing, with a correlation higher than 99% between both methodologies. After the previously reported introduction of the Gamma VOC since the beginning of the year 2021, the variants Alpha VOC and Lambda VOI were detected as early as March 2021, at a very low frequency. In contrast, the Mu VOI, detected in May 2021, was able to circulate throughout the country. After the detection of Delta VOC in June 2021, it be-came the predominant circulating variant. With the arrival of the Omicron VOC in December, this variant was able to displace the Delta one in less than one month. This succession of variants was accompanied by a reduction in the Cycle threshold (Ct) values, in agreement with the in-crease in transmissibility described for these variants.